A Meter for Measuring Signal-to-Noise Ratio in Television Transmission Systems

Three independent characteristic factors affect TV transmission picture quality: linear distortions, nonlinear distortions and noise. A new improved instrument has been developed for the measurement and analysis of video noise in accordance with CCIR Recommendation 421.2. This video noise meter has both true rms and peak-to-peak calibration for objective measurement of random, periodic and impulse noise. Highpass, lowpass and weighting filters permit detailed qualitative and quantitative analysis of the noise, including hum. By interchanging filter modules and resetting an internal switch, one can use the same instrument for both NTSC and PAL Standards. A built-in sag and tilt compensating circuit eliminates pseudonoise components such as are generated by shading of video pickup tubes. The instrument has an accuracy and repeatability of better than 0.5 dB and has a dynamic range of 85 dB, permitting testing of both subassemblies and complete systems.

Print ISSN

0361-4573

Published

1973-04

Content type

Original Research

DOI

10.5594/J08886